Pascua Yaqui Tribe Athletic Commission rules Oscar Valdez can proceed with his fight vs. Robson Conceicao next week, sources say

Oscar Valdez can proceed with his ESPN+ main event fight vs. Robson Conceicao on Sept. 10 in Tucson, Arizona, despite testing positive for the banned substance phentermine, the Pascua Yaqui Tribe Athletic Commission ruled Thursday, sources told ESPN.

In a statement Friday, Valdez maintained that he never used a banned substance.

"I've never done it, I've always been very respectful for the anti-doping rules ever since I was an amateur Olympian and now as a professional," he said. "Ever since I became a world champion in 2016 I've been tested for more than 30 times. I insisted [enrolling] on the VADA testing myself for the Robson Conceicao fight and put that into my contract."

In an interview with ESPN's Mark Kriegel later Friday, Valdez further maintained that he is a "100% clean fighter."

"I don't know how that got into my body," he told Kriegel. "I know every fighter is responsible for whatever they consume, but on behalf of myself I have no clear answer how they got into my body. I've always been and will always be a clean fighter."

WBC president Mauricio Sulaiman told ESPN on Friday that Valdez won't be stripped of his 130-pound title or face any punishment despite the fact the Mexico-based organization utilizes the Voluntary Anti-Doping Association to test its ranked fighters and champions in the WBC Clean Boxing Program.

"It is simple, this is not a performance-enhancing drug," Sulaiman claimed. "It is like if you take three Red Bulls. In the anti-doping world, there are hundreds of substances. ... If you go to a 7-Eleven and you steal a candy bar, you stole, it's illegal. But that is different from robbing a bank with guns and pistols that will give you seven years in jail.

"Valdez will have absolutely no advantage and the challenger will have no risk."

However, Victor Conte disputes all of those claims.

"I personally have given athletes phentermine, I know what it does," Conte, the founder of BALCO, told ESPN. "It is very powerful. It is like methamphetamine."

Conte served time in prison after pleading guilty to conspiracy to distribute performance-enhancing drugs before founding SNAC, a sports nutrition company.

"You know why it's a performance-enhancing drug? Because it's a central nervous stimulant," he added. "It accelerates your heart rate. It gives you energy. It gives you endurance. It gives you stamina. It makes it easier to breathe. Your training time to exhaustion would be much longer."

Pascua Yaqui Tribe Athletic Commissioner Ernie Gallardo declined to explain why Valdez can proceed to fight when reached by ESPN. Sources said the commission opted to ignore the Voluntary Anti-Doping Association guidelines.

Valdez signed a VADA enrollment form, which lists phentermine as a banned substance. Top Rank routinely enlists the testing agency for its title fights at the request of its top-level boxers, providing more comprehensive testing than the bare bones provided by most state commissions.

In this instance, Valdez requested VADA testing for himself and Conceicao.

The Pascua Yaqui Tribe Athletic Commission only adhered to the World Anti-Doping Agency rules, despite the VADA enrollment forms signed by both fighters. WADA doesn't ban the central nervous stimulant outside of competition; its in-competition period begins at 11:59 p.m. the day before the fight.

Top Rank declined to comment when reached by ESPN. Valdez's manager, Frank Espinoza, didn't return a phone call. Conceicao's manager, Sergio Batarelli, said he would comment when he had the "details about the approval."

In his interview with Kriegel, Valdez was asked if he would proceed with the fight if he were Conceicao.

"If I was him, I 100% fight me, because this is a chance to win a world title. The world title is still on the line," Valdez told Kriegel.

Valdez's A- and B-samples were collected on Aug. 13, per sources. Both tested positive for phentermine. The 30-year-old was notified of the A-sample result on Aug. 28. The B-sample result was returned on Sept. 2.

He was tested again on Aug. 30. That test result showed no phentermine in his system. The half-life of phentermine is roughly 20 hours. It takes five to six half-lives for the substance to be fully eliminated from the system (a maximum of six days). The Aug. 30 test was 17 days later.

Valdez, a two-time Olympian from Mexico, "had no knowledge that he was taking phentermine" and believed the substance came from an herbal tea, his lawyer, Pat English, argued in a letter written on Tuesday.

VADA reports adverse analytical findings; it does not adjudicate. However, there is precedent for VADA's rules leading to punishment. Billy Joe Saunders tested positive for the banned stimulant oxilofrine ahead of his scheduled title defense vs. Demetrius Andrade in 2018. The substance was deemed out of competition by WADA, yet Massachusetts recognized the VADA violation and suspended Saunders. The fight was cancelled as a result.

Valdez, ESPN's No. 1 junior lightweight, won the title with a spectacular one-punch knockout of Miguel Berchelt in February, the leading contender for KO of the Year. Valdez (29-0, 23 KOs) was also a champion at 126 pounds.

He was defeated by Conceicao when they met in the gold medal match of the 2009 Pan American Games. Conceicao (16-0, 8 KOs) went on to win gold at the 2016 Olympic Games. The 32-year-old Brazilian is unranked by ESPN.